Style a feature layer

Learn how to use data-driven styling to apply symbol colors and styles to feature layers.

A feature layer is a dataset in a feature service hosted in ArcGIS. Each feature layer contains features with a single geometry type (point, line, or polygon), and a set of attributes.

In this tutorial, you apply different styles to enhance the visualization of the Trailheads, Trails and Parks and Open Spaces feature layers.

Prerequisites

You need a free ArcGIS developer account to access your dashboard and API keys. The API key must be scoped to access the services used in this tutorial.

Steps

Create a new pen

  1. To get started, either complete the Display a map tutorial or .

Set the API key

To access ArcGIS location services, you need an API key.

  1. Go to your dashboard to get an API key.

  2. In CodePen, update apiKey to use your key.

    Change line
                                                             
    <!DOCTYPE html>
    <html>
    
    <head>
      <meta charset="utf-8">
      <meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
      <title>Esri Leaflet</title>
    
      <!-- Load Leaflet from CDN -->
      <link rel="stylesheet" href="https://unpkg.com/leaflet@1.7.1/dist/leaflet.css"
        integrity="sha512-xodZBNTC5n17Xt2atTPuE1HxjVMSvLVW9ocqUKLsCC5CXdbqCmblAshOMAS6/keqq/sMZMZ19scR4PsZChSR7A=="
        crossorigin=""/>
      <script src="https://unpkg.com/leaflet@1.7.1/dist/leaflet.js"
        integrity="sha512-XQoYMqMTK8LvdxXYG3nZ448hOEQiglfqkJs1NOQV44cWnUrBc8PkAOcXy20w0vlaXaVUearIOBhiXZ5V3ynxwA=="
        crossorigin=""></script>
    
      <!-- Load Esri Leaflet from CDN -->
      <script src="https://unpkg.com/esri-leaflet@3.0.0/dist/esri-leaflet.js"></script>
      <script src="https://unpkg.com/esri-leaflet-vector@3.0.0/dist/esri-leaflet-vector.js"></script>
    
      <style>
        body { margin:0; padding:0; }
        #map {
            position: absolute;
            top:0;
            bottom:0;
            right:0;
            left:0;
            font-family: Arial, Helvetica, sans-serif;
            font-size: 14px;
            color: #323232;
          }
      </style>
    
    </head>
    
    <body>
      <div id="map"></div>
    
      <script>
    
        const apiKey = "YOUR-API-KEY";
        const basemapEnum = "ArcGIS:Streets";
    
        const map = L.map('map', {
          minZoom: 2
        }).setView([34.02,-118.805], 13);
    
        L.esri.Vector.vectorBasemapLayer(basemapEnum, {
          apiKey: apiKey
        }).addTo(map);
    
      </script>
    
    </body>
    
    </html>

Add code to style layers

Add the following code to style the Trailheads, Trails and Parks and Open Spaces feature layers:

  • Add Trailheads with hiking icons.
  • Add Trails and style the width and color of the lines.
  • Add Trails again to show bike-only trails.
  • Add Parks and Open Spaces classified by type of park.
Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.Add line.
                                                                                                                                                                                  
<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
  <title>Esri Leaflet</title>

  <!-- Load Leaflet from CDN -->
  <link rel="stylesheet" href="https://unpkg.com/leaflet@1.7.1/dist/leaflet.css"
    integrity="sha512-xodZBNTC5n17Xt2atTPuE1HxjVMSvLVW9ocqUKLsCC5CXdbqCmblAshOMAS6/keqq/sMZMZ19scR4PsZChSR7A=="
    crossorigin=""/>
<script src="https://unpkg.com/leaflet@1.7.1/dist/leaflet.js"
    integrity="sha512-XQoYMqMTK8LvdxXYG3nZ448hOEQiglfqkJs1NOQV44cWnUrBc8PkAOcXy20w0vlaXaVUearIOBhiXZ5V3ynxwA=="
    crossorigin=""></script>

  <!-- Load Esri Leaflet from CDN -->
  <script src="https://unpkg.com/esri-leaflet@3.0.0/dist/esri-leaflet.js"></script>
  <script src="https://unpkg.com/esri-leaflet-vector@3.0.0/dist/esri-leaflet-vector.js"></script>

  <style>
    body { margin:0; padding:0; }
    #map {
      position: absolute;
      top:0;
      bottom:0;
      right:0;
      left:0;
      font-family: Arial, Helvetica, sans-serif;
      font-size: 14px;
      color: #323232;
    }

    .label {
      text-align: center;
      margin-top: -1em;

      size: 12px;
      line-height: 12px;
      font-family: "Noto Sans";
      font-style: italic;
    }

    .label div {
      position: relative;
      left: -50%;
      top: 20px;
      width: 500px;
      text-shadow: 0px 2px 1px rgba(255,255,255,0.85);
    }

  </style>

</head>

<body>

  <div id="map"></div>

  <script>

    const apiKey = "YOUR-API-KEY";
    const basemapEnum = "ArcGIS:Topographic";

    const map = L.map("map", {
      minZoom: 2
    }).setView([34.02,-118.805], 13);

    L.esri.Vector.vectorBasemapLayer(basemapEnum, {
      apiKey: apiKey
    }).addTo(map);



    // Style trailheads (points)
    const icon = L.icon({
      iconUrl: "http://static.arcgis.com/images/Symbols/NPS/npsPictograph_0231b.png",
      iconSize: [18, 18]
    });

    const trailheads = L.esri.featureLayer({
      url: "https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/Trailheads/FeatureServer/0",
      pointToLayer: (geojson, latlng) => {
        return L.marker(latlng, {
          icon: icon
        });
      }
    }).addTo(map);

    // Style trails (lines)
    map.createPane("trails");
    L.esri.featureLayer({
      url: "https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/Trails/FeatureServer/0",
      pane: "trails",
      style: (feature) => {
        const width = 3 + (4 * feature.properties.ELEV_GAIN) / 2300;
        return {
          color: "#BA55D3",
          width: width
        };
      }
    }).addTo(map);

    // Style bike-only trails (lines)
    map.createPane("bikeTrails")
    L.esri.featureLayer({
      url: "https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/Trails/FeatureServer/0",
      where: "USE_BIKE = 'YES'",
      pane: "bikeTrails",
      style: () => {
        return {
          color: "#FFFFFF",
          dashArray: "2, 3",
          dashOffset: "2",
          weight: "1.5"
        };
      }
    }).addTo(map);

    // Style open spaces (polygons)
    L.esri.featureLayer({
      url: "https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/Parks_and_Open_Space/FeatureServer/0",
      style: (feature) => {
        let style = {
          color: null // no outline color
        }
        if (feature.properties.TYPE === "Natural Areas") {
          style.fillColor =  "#9E559C";
        } else if (feature.properties.TYPE === "Regional Open Space") {
          style.fillColor =  "#A7C636";
        } else if (feature.properties.TYPE === "Local Park") {
          style.fillColor =  "#149ECE";
        } else {
          style.fillColor =  "#ED5151";
        }

        return style;
      }
    }).addTo(map);


    // Labels for Trailheads
    // var labels = {};

    // trailheads.on("createfeature", function (e) {
    //   var id = e.feature.id;
    //   var feature = trailheads.getFeature(id);
    //   var center = feature.getLatLng();
    //   var label = L.marker(center, {
    //     icon: L.divIcon({
    //       iconSize: null,
    //       className: "label",
    //       html: "<div>" + e.feature.properties.TRL_NAME + "</div>"
    //     })
    //   }).addTo(map);
    //   labels[id] = label;
    // });

    // trailheads.on("addfeature", function (e) {
    //   var label = labels[e.feature.id];
    //   if (label) {
    //     label.addTo(map);
    //   }
    // });

    // trailheads.on("removefeature", function (e) {
    //   var label = labels[e.feature.id];
    //   if (label) {
    //     map.removeLayer(label);
    //   }
    // });


  </script>

</body>

</html>

Run the app

In CodePen, run your code to display the map.

You should now see the styled trailheads, trails, and parks layers.

What's next?

Learn how to use additional ArcGIS location services in these tutorials: